Device for cutting sheet material



June 30, 1970 M KROFTA 3,517,578

DEvIcE FOR CUTTING SHEET MATERIAL Filed June e, 1968 2 sheets-(sheet 1 Fly'. 2 v

lb ven far Miles khfn June 30, 1970 M. KROFTA DEVICE FOR CUTTING SHEET MATERIAL 2 Sheets-Sheet 2 Filed June 6, 1968 y/Mentor: l Ms 'QJQ.,

Mis-MMX 3,517,578 Patented June 30, 1970 3,517,578 DEVICE FOR CU'I'llNG SHEET MATERIAL Milos Krofta, 58 Yokun Ave., Lenox, Mass. 01240 Filed June 6, 1968, Ser. No. 734,915 Claims priority, application Germany, June 7, 1967,

,561,667 Int. Cl. B26f 3 00; D21f 13/08 U.S. Cl. '83-98 4 Claims ABSTRACT F THE DISCLOSURE A cutting device for rolled sheet material has a nozzle carrying pipe near the roll exterior that can be shifted axially and turned about its axis, and high pressure uid jets emanate from the nozzles towards the sheet material to cut it.

The invention refers to a device for cutting and removing paper board layers or similar sheet material, which is wound on the forming roll of a board machine.

The board is formed by winding several layers of paper liber sheets on the forming roll. When the mat reaches the desired thickness, it has to be cut and removed from the forming roll.

Most frequently there has been used for that purpose a manually operated knife that slices the paper board lengthwise on the forming roll; the roll needs to be provided with at least one groove for the knife. A sharp cutting edge is obtained in this way, but the speed is limited due to the manual operation of the knife.

Another known system for cutting is to apply high pressure air or water. In such a case inside the forming roll, which is provided with at least one groove running the total length of the roll, a pipe with a slot is incorporated. Through such pipe, compressed air is released over the whole length of the roll at desired intervals. In this way the separated board edges are not neatly cut and tend to be torn and uneven through the forceful bursting. The consumption of compressed air is high.

To improve this system, it is known, to use instead of the lixed pressure pipe installed behind the slot length- Wise on the forming roll, a pressure pipe with several nozzles for the outlet of water under pressure. Such pressure pipe is movable in the lengthwise direction so that the board is cut by a series of short cuts caused by the thin sharp jet of the pressure medium. In this way the consumption of the pressure media is reduced but a clean, smooth cutting edge on the mat is still not obtained. The further disadvantage is that it requires a complete longitudinal slot in the forming roll and the cutting can take place only on one spot of the roll where the pressure pipe is located. If the cutting of the board is required on several locations on the forming roll, more slots in the forming roll and more high pressure nozzle pipes need to be installed. The connection of several high-pressure nozzle pipes to the high-pressure source, proves to be rather difcult. If the pressure source is a pump, the connections to the pressure pipe incorporated in the rotating forming roll require rotary joints which at pressures of 1500 p.s.i. are kept tight only with diiiiculty.

There also is the danger to the surrounding by the highpressure jets and some arrangement of shielding otf is required.

It is accordingly among the principal objects of this invention to avoid these disadvantages and to obtain a clean, smooth separating cut, in any place of the forming roll, without endangering the surroundings, with only one single high-pressure nozzle pipe, which can be installed as an addition to any existing forming roll at the outside of it and without any high-pressure rotary joints.

This invention solves the problem inthe following way:

Next to the forming roll there is installed a high-pressure nozzle pipe, parallel to the axis of the forming roll,

movable lengthwise and movable about its own axis y throughout an arc. The high-pressure liuid jets from the nozzles of the pressure pipe cut the board-mat from the outside, by lengthwise movement of the pressure pipe. The cutting takes place against the hard background of the forming roll, producing a clean and sharp cutting edge. A shielding of the high-pressure jets against the surrounding is not required. A fitting of the high-pressure nozzle pipe is easily possible on any type of forming roll, and can be fitted to exchanged forming rolls of different diameter. The operation of the jets can be set at any desired interval and the cuts of the board mat of various sizes may be obtained.

The high-pressure4 nozzle pipe may be supported on both ends of rotating sliding bearings. At least at one side, a lever is located which reaches to the one side of the forming roll, and is activated by a pin located on the side of the forming roll and moved in an arc form. During this rotational movement, the nozzle pipe is moved in axial direction by any kind of conventional means such as by a lever, magnet, pressure operated piston or the like. From the end position the nozzle pipe is moved back into the starting position by any adequate well-known device.

On the drawing there is shown one example of the invention and the following details are explained:

FIG. l is a schematic side elevational view, partly in section, showing a layout of an intermittent board machine with the high-pressure nozzle pipe, according to the invention;

FIG. 2 is a schematic perspective view of the forming roll of the board machine with the cut-olf device with accessories;

FIG. 3 is a fragmentary longitudinal sectional view of one side of the cut-off device with accessories;

FIG. 4 is a sectional view taken on the lines A-A of FIG. 3;

FIG. 5 is a side elevational view, partly in section taken on the line B-B of FIG. 6, of the forming roll with the cut-oil device in the starting position; and

FIG. 6 is a fragmentary sectional view of the cut-olf device.

The cut-off device according to this invention, as shown on FIG. l, is applied to a simple intermittent board machine. The metal wire covered drum of this cylinder machine is immersed into the vat Z lilled with diluted paperstock. During the rotation of the wire covered drum 1, the paper stock sheet is formed on the surface of the drum, the water passes the screen, and flows on both sides out of the drum. After emerging from the vat, the paper mat is picked up by a seamless band 3 which runs over severalrolls to the forming roll 4 on which the sheet is rolled up. When the desired thickness of the paper mat is obtained, a sensor 5 measures for instance the thickness and triggers the cut-01T device which cuts oil the board mat on the forming roll. The lboard mat falls normally through its own weight onto a conveyor 6, and is transported to further processing stages. The board mat dropoff can be accelerated by the use of blow-off nozzles 7, which are installed in the forming roll body and can be supplied with compressed air after the board mat has 'been cut. The equipment for the supply of the compressed air is not shown, since it is not essential, for the description of the cut-off device.

The cut-oil device is composed of a high-pressure nozzle pipe 8 on which nozzles 9 are located in equal distances, for instance four inches apart, depending on the rotational speed of the forming roll and the desired precision of the cuts. The nozzles 9 are made of ceramic in stainless steel holders, with orifices of a size of from 12/1000 to 29/1000, installed parallel to each other. The pipe 8 with nozzles 9 is supported on both sides at 10 and 11 in the way that it can rotate in an arc and be shifted lengthwise in the direction of its axis of rotation for the. distance between two nozzles 9. To shift the pipe lengthwise, a piston '12 is placed on the extension of the nozzle pipe, moving to the left in the hollow cylinder 13 which is part of `the bearing 11 by the pressure medium arriving through the pipeline 14. At the same time at the opposite end of the nozzle pipe a spring 15 is compressed against the bearing 10. At the end of the piston stroke, the bearing rod 16 of the nozzle pipe, will make Contact with the switch 17 on the bearing 10, which, as it will be explained later, will disconnect the shifting mechanism, and will interrupt the delivery of the pressure medium to the nozzle pipe through the line 18, which feeds during the operation the nozzles 9 and forms the cutting jets. To produce a clean and linear cut, the jets must follow the same arc which is traveled by the forming roll during the cutting process. A device rotating the nozzle pipe for this purpose is described below.

Fastened by a key on the shaft of the piston 12, there is mounted a holder 19 for a lever 20. When the cut-01T of the board should take place, the lever 20, through application of power, in this case a magnetic power, moves from the starting position (FIGS. 3 and 6), to the linal position (FIGS. 2 and 5). The cut-01T starts when the lever 20 is taken along by the pin 21, mounted on the side of the forming roll 4. The lever 20 follows the arc 22 (FIG. 5) and stops at the end, while the pin 21 continues upwardly. Actuated by the spring 15, the nozzle pipe `8 returns into the starting position (FIG. 3), at the same time it swings back over the arc 22 actuated by own weight or by a spring connected to the holder 19, and the lever 20 returns to its original position.

The teed of the pressure media required for the cut is actuated at the same time when the pin 21 strikes the lever 20, moving the cam 23I located on the outside of the support '19 and pressing the contact switch 24. The latter closes the power circuit 25 and with it opens the magnetic valve 28 (FIG. 2) of the continuously pressurized supply line 18. The magnetic valve 28 opens or closes the connecting line to the pressure tank 26 which is fed by the pump 27. This pump starts, independently from the cut-ol timing, lby falling pressure in the tank 26v and shuts off at high pressure.

In a side line 14 branching off the line 18, a pressure reducing valve 30 (FIG. 2) is located, that reduces the pressure in the line 14 to a pressure adequate for the piston 12. This piston can also be operated by compressed air.

A safeguard is provided around the nozzzle pipe 8, to prevent the spraying of the pressurized water on the board mat before the required pressure of 200G-3000 .ps i. is reached in the nozzle outlet and after the cut-oil is completed. The safeguard is composed of a fixed slotted pipe 31 (FIG. 5) which surrounds the nozzle pipe 8. The slot is adjustable on one side by means of a guard plate 33, which is fastened by means of hand screws. At

the opposite side there is provided a spring 'biased sheet screen 36, which closes the slot almost to the guard plate 33. The sheet screen 36 is taken along by the movement of the nozzle pipe 8 through a connecting device-not shown in the drawing-until the desired width of the slot is obtained.

The cutting starts when the jets from nozzles 9 emerge from under the guard plate 3,3 and ends when the jets disappear under the opposite guard plate. The sheet screen 36, actuated by a spring closes the slot, to prevent the spraying of board and wetting it.

The installation operates as follows. When the desired thickness of the board mat is reached on the forming roll 4, it touches the sensor 5 (see FIG. 5), which starts the power circuit 34 and actuates the solenoid on the holder 19 (FIG. 3), by passing the central control panel, connecting all electrical lines, and the lever 20 is extended. The pin 21 on the forming roll 4 catches the lever 20 and swivels the nozzle pipe 8 along the arc 22. At the same time when the pin 21 moves the lever 20, the cam 23 runs over the switch 24. The power circuit 25 is closed, and opens the solenoid valve 28. Now the medium will flow in the pressure pipe and the connecting line under pressure and will emerge as jets from the nozzles 9, striking the internal side of the guard plate 33 which is located on the safeguard cylinder 31. At the same time the piston 12 is pressurized through the side line 14 and moves the pressure pipe 8 in axial direction along the forming roll. At the end of the axial movement, the switch 17 closes. This actuates the circuit and closes the solenoid valve 28 and only the leftover water is discharged. The spraying on the froming roll is prevented by the sheet screen 36 which closes the slot. At the same time the power in the line 24 is cut off. Because of it the lever 20 is retracted by means of an auxiliary force. The cutting process is terminated. The cutting cycle starts again when the board mat on the forming roll accumulates to the requested thickness and touches the sensor 5 which starts the cycle.

I wish it to be understood that I do not desire to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.

Having thus described the invention, what I claim as new and desire to be secured by Letters Patent, is as follows:

1. A cutting device, for use in connection with a rotor rotatable about a iirst axis and carrying rolled sheet material, said cutting device comprising in combination a pipe disposed adjacent said rolled sheet material and having a second axis substantially parallel to said rst axis and having nozzles intercommunicating interiorly with said pipe and adapted to be fed a pressure medium and to discharge the medium in the form of jets towards said rolled sheet material, said pipe being shiftable axially, oppositely, along its second axis and turnable for severing said sheet material along a substantially uninterrupted line substantially parallel to said axes.

2. A cutting device, as claimed in claim 1, a projection mounted on said rotor, said pipe mounting a lever operable to project into the path of said projection to be engaged and moved by the projection, whereby said pipe will be turned throughout an arc during selected revolutions of said rotor for cutting a predetermined length of said sheet material, means operable for shifting said pipe axially in one longitudinal direction, and restoring means operative to return the pipe to its initialposition near the end of each cutting operation.

3. A cutting device, as claimed in claim 1, said rotor including a shell supporting said rolled sheet material, said shell having spray nozzles for conducting a spray uid from inside said shell towards said sheet material.

4. A cutting device, as claimed in claim 1, and a safety guard surrounding said pipe and delining in front of said nozzles an elongated slot, means including a guard plate 6 operable to adjust the width of said slot and to close FOREIGN PATENTS it after the cutting operation has been completed. 860,890 12/1952 Germany' References Cited 860891 12/1952" Germany' UNITED STATES PATENTS 5 WILLIAM S. LAWSON, Primary Examiner 1,225,778 5/ 1917 Cram et al. 162-285 Y 2,396,104 3/1946 Kingman 162-285 X U-S' C1' XR 2,445,254 7/ 1948 Winterburn 162-285 83-177162--285 

